Pool structure



June 27, 1961 s. 1 FRIEDLANDER ET Ax. 2,989,757

Poor. STRUCTURE Filed Nov. 24. 1958 2 sheets-sheet 1 JNVENTORS June 27,1961 s. L. FRIEDLANDER ETAL 2,989,757

POOL STRUCTURE 2 Sheet s-Sheet 2 Filed NGV. 24, 1958 e. .J @H Ww w F s Wy Q on 2 w n nite This invention relates to an improvement in a poolliner, particularly of the type adapted for use in wading pools, and ismore particularly concerned with a novel plastic wading pool liner andthe process for producing same.

It has been customary practice in the manufacture of portable wadingpools, for example, of the type especially adapted to be placed in ayard for use by children, to support a flexible plastic liner on acylindrical or oval shaped ring support. The liner has la downwardlydepending bottom portion and a cylindrical or oval shaped side portion,the upper edge of which is bent over and around the upper edge of thesupport and maintained in position thereon to thus support the plasticliner about and within the ring when the liner is lled with water.

FIGURES l to 4 of the yaccompanying drawing illustrate one mode of priorart practice for constructing the prior art liner of such portablewading pools. FIG. l shows a plan view of the bottom port-ion of theliner, and FIG. 2 is a vertical section taken on line 2--2 of FIG. l,showing lthe side portion of the liner and the support therefor. It willbe noted from FIG. 1 that the circular bottom portion 11 of the liner 10is formed of pieces 12, 13 and 14 which are sealed along parallel chords15. While three pieces are shown, more are also used, the adjacentpieces being generally sealed along parallel chords such aS 15.

Referring to FIGS. 3 and 4, showing the prior art manner of fabricatingthe proper shapes for pieces 12, 13 and 14 from sheet plastic, eg., avinyl plastic, the center piece 13 is formed from a rectangular sheet16, shown in FIG. 3, which is cut adjacent its opposite ends to formarcs `17. This produces waste end strips of plastic 18 cut from thesheet 16. Further, in forming the two outer semicircular shape portions12 and 14 of the bottom 11, these portions are generally cut from alength of plastic sheeting indicated at 19 in FIG. 4. The members 12 and14 are cut in opposite alternating fashion from the strip 19, as shownin FIG. 4, leaving adjacent strips of sheeting 20 as waste material. Thestrips 12 and 14 are then sealed along adjacent edges to the centerstrip 13 to form the bottom 11 of the liner. It is thus seen that thereis a substantial amount of wasted plastic sheeting material resultingform the prior art practice of forming the bottom portion `11 of theliner, and in view of the relatively high price of plastic sheeting,e.g. vinyl plastics, for this purpose, such Waste represents aconsiderable loss, especially since pools of this type are manufacturedon a volume basis with cost of production a vital factor.

Further, as shown in FIG. 2, according to such prior art practice thecylindrical side portion 21 of the liner 10, which is supported from itsupper edge on a ring shaped vertically positioned support, e.g., a Wiremesh type support, indicated at 22, is sealed around its bottom edge tothe outer periphery of the bottom portion 11 of the liner. This sealindicated at 23 may be formed by any of the various types ofconventional welds, for example, a butt weld as shown in FIG. 2. Thisweld which joins the bottom 11 and the side wall 21 of the liner wherethey intersect at right angles to each other, forms a line of weakness,and when water is placed in the pool considerable strain is developed atthe weld 23, particularly when there is movement of the body of water inthe tates Patent C) liner, often causing the liner to rupture at suchweld or seal. Where a lap weld is employed for sealing at 23 instead ofa butt weld, the seal between the intersection of the bottom 11 and theside wall 21 is strengthened, but a lap weld of this nature, asindicated at 23 in FIG. 2a, can only be produced using expensive diesand fixtures, the cost of which increases still further as the diameterof bottom 11 of the liner increases.

It is an object of this invention to provide a pool structure having aflexible plastic liner formed of a plurality of plastic sheets shapedand connected together in such manner as to reduce the amount of wastageof material resulting from prior art practice.

It is another object to provide a pool structure having a flexibleplastic liner formed of a plurality of plastic sheets shaped and sealedtogether in a manner to avoid the use of a peripheral seal between thebottom edge of the liner side wall and the outer periphery of the linerbottom portion.

Still another object is the provision of a novel iiexible plastic liner,especially adapted for wading pools, and having increased resistance torupture 'as compared to prior art liners and providing greater economyin fabrication.

A still further object is the provision of procedure for fabricating theaforementioned Iflexible liner.

According to a preferred embodiment of the invention, we have provided apool liner, preferably one adapted to be supported on a ring shapedmember, formed of a plurality of pie shaped sheets of flexible,preferably plastic sheet material, e.g., vinyl plastic, each preshapedpiece having an integral outer extension or flap with parallel sideedges. The adjacent pie shaped sections are sealed together along theirradially extending edges to form the bottom of the liner, and theaforementioned extensions or flaps are sealed together along adjacentparallel edges and bend upward from the plane of the pie sections, toform the outer peripheral wall of the liner, which extends upwardlysubstantially at right angles to the bottom portion of the liner. Theupper portion of the liner wall is bent back over the top edge of a ringshaped liner support, e.g., in the form of a wire mesh ring, and can besecured in this manner, if desired, by a suitable clamp member.

In the liner so produced, since the pie `shaped sections form the bottomof the liner and the outer extensions thereof form the side wall of theliner, there is no need for a separate bottom portion and a separatewall portion and hence no requirement for producing a seal at theintersections of these respective portions. Hence, in the linerconstruction according to the invention, the pe- -ripheral seal formedbetween the lower edge of the prior art liner side wall and fthe outerperiphery of the prior art liner bottom portion, eg., as shown at 23 inFIG. 2, is avoided, and there is thus a of sealing or welding at theintersection of the liner bottom portion and the liner side wall in theliner ofthe invention. This results in a liner which has substantiallyenhanced strength and hence aifords much less danger of rupture thanconventional liners.

Further, by forming pie shaped sections with integral outer extensionsfrom plastic sheet material and by sealing said pie shaped sections `andextensions together as indicated above and in the manner described indetail hereinafter, there is practically no Wasted material resultingfrom the fabrication process, thus providing substantial economics inproduction.

The invention will be more fully understood by reference to thedescription Ibelow, taken in connection with FIGS. 5 to 1l of theaccompanying drawings wherein:

FIG. 5 is a perspective view kof a pool embodying a flexible lineraccording to the invention;

FIG. 6 is a vertical section taken on line 6-6 of FIG.

FIG. 7 shows the manner of cutting a plastic sheet to form pie shapedsections and extensions used in fabricating the invention liner;

FIG. 8 shows the manner of sealing one type of pie shaped section formedby the cutting technique of FIG. 7;

FIG. 9 shows another way of producing pie shaped sections from portionsof the aforementioned cut sheet;

FIG. 9a shows the manner of sealing the type of pie shaped sectionsproduced according to FIG. 9;

FIG. 10 shows application of the invention principles to another form ofpool; and

FIG. 11 is a section taken on line 11-11 of FIG. 10.

Referring to FIGS. 5 and 6, the bottom 26 of the liner is composed of anumber of pie sections 27, herein shown as ten in number, radiatingoutwardly from the center of the bottom 26. The pie sections each haveextensions 28 at their outer ends, said extensions each having paralleledges 31 and being bent upwardly at about a 90 angle to the piesections, forming the outer wall 29 of the liner. The pie sections aresealed together along their adjacent edges and the extensions 28 thereofare sealed `together along their adjacent parallel edges 31.

Now referring to FIG. 7 showing the first step in the technique forfabricating the liner of FIGS. 5 and 6, a number of like rectangularsheets of plastic 32 are provided or cut out from a large sheet of aexible plastic, preferably a plastic material of good strength and waterimpermeability characteristics, e.g., a vinyl plastic. Ihe width ofsheets 32 is chosen in accordance with predetermined circumference ofthe pool liner and the number of pie shaped sections to be employed.While the number of pie shaped sections shown in FIG. 5 is illustratedas ten, it will of course be understood that more or less can beemployed. The length of sheets 32 is chosen such as to equal the sum oftwice the height of the wall portion 29, plus the approximate radiallength of the pie shaped section 27, for a purpose which will be madeclear below.

Leaving at one end 28a a sufficient amount of material to form theextension or flap 28, the pie shaped section 27 is cut out as indicatedby dotted lines along the edges 30 of the pie section. This leavesanother notched section 35 having a pair of wedge portions 41 and an endportion 44, which section can be employed alternatively to pie shapedsections 27 to form the liner of the invention in a manner describedmore fully below.

Referring now to FIG. 8, it is seen that one pie section dielectric heatsealing, forming, for example, a lap weldV indicated at 36, along thesealed edges. If desired, a butt weld can be employed instead of a lapweld. As each of the adjacent pie sections 27 and each of the adjacentouter extensions 28 is sealed along their outer edges it will be notedthat `the extensions 28 curl or bend up at their intersections with therespective pie sections due to the parallel edges 31 of said extensionsnot being in direct alignment with the divergent radial edges 30 of theattached pie sections 27. Thus, when all of the pie sections 27 andtheir respective outer extensions or flaps 28 have been sealed alongtheir edges in the manner above described, the flaps 28 will form anessentially vertical wall portion 29 integrally connected to the bottomportion 26 `formed by `the sealed-together pie sections.

It will be noted that the liner so formed has no circumferential sealline or weld between the bottom portion 26 and the wall portion 29,` andthat there is but a-minimum of sealing at points indicated by numeral36',

4. at the intersection of the bottom and wall surfaces 26 and 29 of theliner, the peripheral intersection between these surfaces beingotherwise unwelded. Also, of particular significance, it is noted thatsince thc sealing lines 30 and 31 between the adjacent pie sections 27and their respective outer extensions 28 extend in an outwardessentially radial direction from the center of the liner, and since theforce developed by the mass of water in the liner is directed outwardagainst the side wall 29 of the liner which is in turn rigidly supportedagainst the ring support, there is a minimum of tensile stress developedin opposite directions across the sealing lines 30 and 31. On the otherhand, the conventional peripheral seal of conventional liners, eg., 23in FIG. 2, extending around the circumference of the bottom of the lineris subject to a substantial strain due to the force exerted by the wateracting on the liner wall just above the circumferential seal and aroundthe bend formed at the circumferential seal and against the adjacentouter peripheral portion of the liner bottom, tending to bulge out theliner at the bottom adjacent the peripheral seal. These forces act inopposite directions across the circumferential seal, inducingsubstantial tensile stress all along the peripheral seal.

It will be noted that While the liner is stated to be substantiallycircular, actually the upstanding portions 28 are straight rather thancurved, viewing FIG. 8, and together form a decagon, rather than a purecircle. However, when these end portions 28 are supported in the mannernoted below, said end portions are slightly stretched, and tend to forma circle so that the liner wall 29 is essentially cylindrical in shape.

The upper end portions 32 of the wall 29 formed by extensions 28 can bestretched over and around the top of a circular ring support for theliner, such as a wire mesh ring 39. Such ring should be sufficientlyrigid to support the wall portion 29 and prevent its bowing out whenwater is placed in the pool. Other suitable and known types of ringsupports can be used, if desired, such as a solid metal ring formed ofaluminum, galvanized metal, masonite or concrete. Preferably, a clampingmember 40, e.g. in the form of a ring of extruded plastic such aspolyethylene, can be clamped over the upper peripheral edge portion ofthe wall 29 and the upper supporting edge of the wire mesh ring, asillustrated in FIG. 6, to maintain the wall portion 29 in position onthe ring 39.

The notched portions 35 (see FIG. 7) which are also cut from the plasticsheets 32, can be utilized to form a liner substantiallythe same as thatshown in FIGS. 5 and 6. Here, however, the two outer wedge portions 41of each of these notched portions are first bent toward each other andsealed together along their edges 42, as indicated at 43- in FIG. 9,causing the outer extension 44 of each of portions 35 to bend upward atits intersection 44' with its two integral wedge portions 41. This formsa pie section 46 similar to pie section 27, with integral extensions 44.The adjacent outwardly diverging edges 45 of adjacently placed piesections 46 are sealed together, and the adjacent substantially paralleledges 47 of the attached extensions 44 are sealed together, e.g., byheat welding in the manner described above and illustrated in FIG. 9a,forming a liner substantially the same as 2S, except that there areadditional welds at 43 down the center of each pie section 46.

In this manner a wading pool liner can be constructed without any wasteof plastic sheeting material, and the liner so constructed is devoid ofthe peripheral seal at the intersection between the bottom and wallportion of the liner, which seal is present in conventional liners.

It will be noted that a liner can be constructed using pie shapedmembers 27 exclusively, pie shaped members 46 exclusively, or using acombination of members 27 and 46.

The principles of the invention can be applied also to pools having ashape other than circular, and to production of pool liners other thanthose utilized for wading pools. Thus, for example, as illustrated inFIGS. and 11, showing an excavated large swimming pool 50, there isshown Va generally semicircular deep end 51 and generally semicircularbut smaller shallow end 52. The deep end portion 51 has a downwardlyinclined bottom portion 53` and the shallow end 52 has a horizontalbottom portion 54. The portion of the liner placed in the deep end canbe formed of a series of adjacent pie sections 55 sealed along theiradjacent edges 56, and a series of adjacent aps or extensions 57integrally connected to each of the pie sections and sealed along theiradjacent edges 58. It will be noted that in view of the downwardlysloping bottom of the deep end of the pool, the bottom 59 of the linerformed by pie sections 55 intersects at 60 the wall portion 60 formed bythe adjacent ilaps 57, at an obtuse angle substantially greater than aright angle.

The liner at the shallow end of the pool is formed of pie sections 61having integral aps or extensions 62, the pie sections being sealedalong their adjacent edges 63 to cover the semicircular bottom of theshallow end, and the ilaps being sealed along their adjacent edges 64 toform the wall portion 65 of the liner. Here, however, the intersectionat 67 between the bottom portion 66 of the liner and the wall portion 65is substantially a right angle, as in the case of the liner 25 of FIG.5, described above.

It is thus seen that we have designed a novel exible liner for use inwading and swimming pools, having improved strength and durability, andwhich is readily fabricated and economical to produce.

While we have described particular embodiments of our invention for thepurpose of illustration, it should be understood that variousmodiiications and adaptations thereof may be made within the spirit ofthe invention as set forth in the appended claims.

We claim:

1. In combination a flexible pool liner and a ring shaped support, saidexible pool liner being mounted Within and about said support, said poolliner having a bottom portion and an upstanding substantiallycylindrical wall portion, and comprising a plurality of planar pieshaped sections formed of a ilexible sheet material, each of saidsections having outwardly diverging radially extending edges and anintegral outer extension in the form of a rectangle, said extensionseach having parallel edges extending from the outer divergent ends ofsaid radially extending edges and at equal angles to said divergentedges, the adjacent pie shaped sections being sealed together alongtheir adjacent radially extending edges from the inner apex of each piesection to the outer ends of said radially extending edges, to form asubstantially circular bottom portion of said liner, said extensionsbeing sealed together along adjacent parallel edges and bent upward fromthe plane of said pie sections at the intersection of said extensionswith said pie sections, said extensions forming said subtantiallycylindrical Wall portion, said `cylindrical wall portion of said poolliner being disposed closely adjacent to and supported by said ringshaped support, the upper end of said cylindrical wall portion beingfolded over the top of said support and around the outer periphery ofsaid support adjacent the top thereof.

2. In combination a flexible pool liner and a wire mesh ring shapedsupport, said flexible pool liner being mounted within and about saidsupport, said pool liner having a bottom portion and an upstandingsubstantially cylindrical wall portion, and comprising a plurality ofplanar pie shaped sections formed of a flexible sheet material, each ofsaid sections having outwardly diverging radially extending edges and anintegral outer extension in the form of a rectangle, said extensionseach having parallel edges extending from the outer divergent ends ofsaid radially extending edges and at equal angles to said divergentedges, the adjacent pie shaped sections being sealed together alongtheir adjacent radially extending edges from the inner apex of each piesection to the outer ends of said radially extending edges, to form asubstantially circular bottom portion of said liner, said extensionsbeing sealed together along adjacent parallel edges and bent upward fromthe plane of said pie sections at the intersection of said extensionswith said pie sections, said extensions forming said substantiallycylindrical wall portion, said cylindrical wall portion of said poolliner being disposed closely adjacent to and supported by said ringshaped support, the upper end of said cylindrical wall portion beingfolded over the top of said support and around the outer periphery ofsaid support adjacent the top thereof, and a clamping ring of channelshaped cross section clamped over the top peripheral edge of said ringshaped support, clamping the adjacent end portion of said pool liner tosaid support.

3. In combination a flexible pool liner and a ring shaped support, saidiiexible pool liner being mounted within said support, said pool linerhaving a bottom portion and an upstanding substantially cylindrical Wallportion, and comprising a plurality of planar pie shaped sections formedof a iiexible sheet material, each of said sections having outwardlydiverging radially extending edges and an integral outer extension inthe form of a rectangle, said extensions each having parallel edgesextending from the outer divergent ends of said radially extendingedges, the adjacent pie shaped sections being sealed together alongtheir adjacent radially extending edges from the inner apex of each piesection to the outer ends of said radially extending edges, to form asubstantially circular bottom portion of said liner, said extensionsbeing sealed together along adjacent parallel edges and bent upward fromthe plane of said pie sections at the intersection of said extensionswith said pie sections, said extensions forming said subtantiallycylindrical wall portion, said cylindrical wall portion of said poolliner being disposed adjacent to the inner periphery of said ring shapedsupport, and means for supporting the upper section of said `cylindricalWall portion around the periphery of said ring shaped support.

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